I amgetting very poor gas millage. I have changed the air filter, plugs and wires. Anyone have a suggestion as to wether I should use an additive, or removal and cleaning? Your help is greatly appreciated.

 

Check for a leaky plenum.

 

Chrysler's official fuel injector cleaner is pretty good
and not too expensive at $6 per bottle
but I think you need 3 bottles in 3 tanks of gasoline

If you want to use another good cleaner for bottles 2 and 3
Techron Concentrate Plus (the Plus is newer & better)
and Yamaha Ring Free are very good too.